1. Field of the Invention
The present invention relates to a surgical instrument, which grasps a living tissue, and coagulates and cuts the tissue by ultrasonic vibration and high-frequency current.
2. Description of the Related Art
Each of an ultrasonic instrument using ultrasonic vibration and a high-frequency instrument using a high-frequency current is known as a surgical instrument. An ultrasonic instrument can coagulate and cut a living tissue by heating the tissue with ultrasonic vibration. A high-frequency instrument can coagulate and cut a living tissue by touching an electrified electrode to the living tissue.
Surgical instruments which can treat a living tissue by using both ultrasonic vibration and high-frequency current are known by Jpn. Pat. Appln. KOKAI Publication Nos. 2003-79633, 2004-12987 and 2004-216180. In each of these surgical instruments, ultrasonic vibration generated by an ultrasonic transducer provided in an operation area is transmitted to a distal end portion of an ultrasonic probe through an ultrasonic vibration transmitting member, and a jaw is provided on the ultrasonic probe to be able to open and close to the probe. The jaw and the probe can grasp a living tissue between them. And, by supplying a high-frequency current from an externally provided high-frequency power supply to the ultrasonic probe, the tissue grasped between the ultrasonic probe and the jaw can be coagulated and cut by the high-frequency current.
The surgical instrument described in the Jpn. Pat. Appln. KOKAI Publication No. 2003-79633 has a round bar-shaped horn for generating ultrasonic vibration, and an open/close cover having an arc-shaped section and an electrode and provided on the horn to open and close thereto. A living tissue is grasped by the horn and cover, and coagulated and cut by the ultrasonic vibration from the horn and high-frequency current from the electrode of the cover. However, in this conventional surgical instrument, there is a problem that the living tissue cannot be grasped (compressed) by a strong force because the living tissue is grasped by the round bar-shaped horn and the arc-shaped sectioned open/close cover.
The surgical instrument described in each of the Jpn. Pat. Appln. KOKAI Publication Nos. 2004-129870 and 2004-216180 has a round bar-shaped horn for generating ultrasonic vibration, and a grasping member having an electrode and provided on the horn to open and close thereto. A living tissue is grasped by the horn and the grasping member, and coagulated and cut by the ultrasonic vibration from the horn and high-frequency current from the electrode of the grasping member. However, also in this conventional surgical instrument, there is a problem that the living tissue cannot be grasped (compressed) by a strong force because the living tissue is grasped by the round bar-shaped horn and the grasping member.